package com.example.xpvideo.tools;


import java.util.Random;

public class ShareCode {
    /** 自定义进制(0,1没有加入,容易与o,l混淆) */
    private static final char[] r = new char[]{'Q','W','E','R','T','Y','U','I','O','P','A','S','D','F',
            'G','H','J','K','L','Z','X','C','V','B','N','M'};

    /** (不能与自定义进制有重复) */
    private static final char b = 'O';

    /** 进制长度 */
    private static final int binLen = r.length;

    /** 序列最小长度 */
    private static final int s = 5;

    /**
     * 根据ID生成六位随机码
     *
     * @param id ID
     * @return 随机码
     */
    public static String toSerialCode(Long id) {
        char[] buf = new char[32];
        int charPos = 32;

        while ((id / binLen) > 0) {
            int ind = (int) (id % binLen);
            buf[--charPos] = r[ind];
            id /= binLen;
        }
        buf[--charPos] = r[(int) (id % binLen)];
        String str = new String(buf, charPos, (32 - charPos));
        // 不够长度的自动随机补全
        if (str.length() < s) {
            StringBuilder sb = new StringBuilder();
            sb.append(b);
            Random rnd = new Random();
            for (int i = 1; i < s - str.length(); i++) {
                sb.append(r[rnd.nextInt(binLen)]);
            }
            str += sb.toString();
        }
        return str;
    }

    public static long codeToId(String code) {
        char[] chs = code.toCharArray();
        long res = 0L;
        for (int i = 0; i < chs.length; i++) {
            int ind = 0;
            for (int j = 0; j < binLen; j++) {
                if (chs[i] == r[j]) {
                    ind = j;
                    break;
                }
            }
            if (chs[i] == b) {
                break;
            }
            if (i > 0) {
                res = res * binLen + ind;
            } else {
                res = ind;
            }
        }
        return res;
    }


    public static void main(String[] args) {
        Long id=9999999L;
        String i = toSerialCode(id);
        System.out.println(i);


        //4Gh4LAZk

    }

}
